Table 2. Meiotic Genes Involved in Homologous Recombination and Synaptonemal Complex Formation.
Homologs of S. cerevisiae genes required for homologous recombination and synaptonemal complex formation were compared across a subset of eukaryotic species. The presence of a gene homolog is designated by ( + ) and absence of a homolog by (−). Genes representing the best markers for predicting the presence of a meiotic pathway (“meiotic toolkit” genes, [52]) are also indicated ( * ). Note that S. pombe does not form synaptonemal complexes but uses linear elements that involve Rec8, Hop1, Hop2, Mek1, and Rec10 (homolog of S. cerevisiae Red1). C. lusitaniae demonstrates meiotic competence culminating in the formation of recombinant spores yet is lacking six of the eight meiotic toolkit genes, as well as homologs of most of the genes associated with synaptonemal complex/linear element formation.
| Genes Involved in Homologous Recombination | |||||
|---|---|---|---|---|---|
| Function of gene product in S. cerevisiae | S. cerevisiae | C. lusitaniae | C. albicans | S. pombe | M. musculus |
| Meiosis specific gene, important for processing dsDNA breaks for repair during homologous recombination. | DMC1* | − | + | + | + |
| Dmc1 cofactor; forms a complex with Sae3 for dsDNA break processing during homologous recombination. | MEI5 | − | + | + | + |
| Meiosis specific helicase. | MER3/HFM1 | − | + | − | + |
| Mismatch repair gene that is important for DNA crossover during meiosis. | MLH1 | + | + | + | + |
| Endonuclease that complexes with MUS81 to cleave branched DNA; involved in joint molecule formation/resolution during recombination. | MMS4 | + | + | + | + |
| Forms a complex with HOP1, important for chromosome pairing and repair of dsDNA breaks. | MND1* | − | + | + | + |
| Subunit of MRX complex, required for dsDNA break repair during homologous recombination. | MRE11 | + | + | + | + |
| Forms a complex with MSH5, essential for regulating crossover events during meiosis. | MSH4* | − | + | − | + |
| Forms a complex with MSH4, essential for regulating crossover events during meiosis. | MSH5* | − | + | − | + |
| Endonuclease that complexes with MMS4 to cleave branched DNA; involved in joint molecule formation/resolution during recombination. | MUS81 | + | + | + | + |
| Subunit of MRX complex, required for dsDNA break repair during homologous recombination. | RAD50 | + | + | + | + |
| Meiotic protein important for strand invasion and exchange during homologous recombination. | RAD51 | + | + | + | + |
| Meiotic protein that stimulates strand exchange during homologous recombination. | RAD52 | + | + | + | + |
| Dmc1 cofactor; forms a complex with Mei5 for dsDNA break processing during homologous recombination. | SAE3 | − | + | + | + |
| Helicase, regulates meiotic crossover formation events. | SGS1 | + | + | + | + |
| Meiosis specific protein that stimulates homologous recombination by catalyzing the formation of dsDNA breaks. | SPO11* | + | + | + | + |
| Component of the MRX complex, important for dsDNA repair during homologous recombination. | XRS2 (NBS1) | − | − | + | + |
| Synaptonemal Complex Genes. | |||||
|---|---|---|---|---|---|
| Function of gene product in S. cerevisiae | S. cerevisiae | C. lusitaniae | C. albicans | S. pombe | M. musculus |
| Meiosis specific protein, localizes to axial elements of the synaptonemal complex. Required for homologous recombination. | HOP1* | − | + | + | + |
| Meiosis protein that promotes recombination between homologous chromosomes and prevents recombination between non- homologous chromosomes. | HOP2* | − | + | + | + |
| Meiosis specific serine/threonine kinase that promotes recombination between homologous chromosomes. | MEK1 | − | + | + | + |
| Sister chromatid cohesin protein. | REC8* | + | + | + | + |
| Protein component of axial element in the synaptonemal complex. | RED1 | − | − | + | + |
| Structural component of synaptonemal complex, promotes recombination between homologs. | ZIP1 | − | − | − | + |
| Meiosis specific protein important for synaptonemal complex formation. | ZIP2 | − | + | − | + |
| Sumo E3 ligase, localizes to synapse initiation sites and is required for synaptonemal complex formation. | ZIP3 | − | + | − | + |
| Meiosis specific gene essential for synapsis during homologous recombination. | ZIP4 | − | − | − | − |